I see a thread from 2007 that says Toxicodendron vernicifluum was removed from the garden, but today Eric La Fountaine told us about it and about Andy Hill's unfortunate run-in with it some time back, so of course we had to go see it. It's just outside the south fence, but safely beyond reach. Actually, we had to ask twice where it was, as I wasn't expecting pinnate leaves and we mistook it for Meliosma, which we would have had our hands all over if that had been possible.
I thought they were fruits too, but they must be flower buds (?), as Plants for a Future says "Partly dioecious. Male and female plants must be grown if seed is required." I'm not sure about the "Partly" dioecious, followed by the bit about male and female plants being required. Anyway, there is only the one tree.
Doesn't look right - it shouldn't be dying off brown like that. Healthy foliage turns spectacular red in the autumn, but not this early.